Abdullah ibn Amr ibn al Aas may Allah be pleased with him reported: A man asked the Messenger of Allah pbuh: "Which deed in Islam is the best?" He said: "Feeding people and extending the greeting of peace to those you know and those you do not know." Agreed upon.

And he pbuh also said: "The best of deeds to Allah Almighty is happiness you bring to a Muslim or a hardship you relieve a Muslim of, or feed him so he will not be hungry, or pay his debt."
فعن عبد الله بن عمرو بن العاص رضي الله عنهما أن رجلا سأل رسول الله صلى الله عليه وسلم: أي الإسلام خير؟ قال: (تطعم الطعام وتقرأ السلام على من عرفت ومن لم تعرف) متفق عليه.

وقال رسول الله صلى الله عليه وسلم: (أحب الأعمال إلى الله سرور تدخله على مسلم، أو تكشف عنه كربة، أو تطرد عنه جوعا، أو تقضي عنه دينا) صحيح الجامع.

2. The Best of People | خير الناس
The best of people are the ones who feed the hungry. The Messenger of Allah pbuh said: "The best of you is one who feeds people and extends the greeting." Narrated by Ahmad.
2. خير الناس من يقوم به
قال رسول الله صلى الله عليه وسلم: (خيركم من أطعم الطعام ورد السلام) رواه أحمد.

3. A Great Reward from Allah | أجر جزيل عند الله
He will gain a great reward from Allah. Aisha may Allah be pleased with her said that the Messenger of Allah pbuh said: "Allah increases the date or a bite of food given in charity, just as one of you brings up a pony until he grows, so it becomes as big as the Mount of Uhud."
3. له أجر جزيل عند الله
ففي مسند الإمام أحمد عن عائشة رضي الله عنها أن رسول الله صلى الله عليه وسلم قال: (إن الله ليربي لأحدكم التمرة واللقمة كما يربي أحدكم فلوة أو فصيله، حتى يكون مثل أحد).

Abu Hurayrah may Allah be pleased with him reported: The Messenger of Allah pbuh said: "Allah, Glorified and Exalted, will say on the Day of Judgment: O son of Adam, I was ill, but you did not visit Me. He will respond: O Lord, how could I visit You and You are the Lord of the worlds? Allah will say: Did you not know that My Servant, so and so, was ill but you did not visit him? Do you not know that if you had visited him, you would have found Me with him? O son of Adam, I asked you for food, but you did not feed Me. He will respond: O Lord, how could I feed You and You are the Lord of the worlds? He will say: Did you not know that My Servant, so and so, asked you for food, but you did not feed him? Do you not know that if you had fed him, you would have found its reward with Me? O son of Adam, I asked you for water, but you did not give Me any. He will respond: O Lord, how could I give You water to drink and You are the Lord of the worlds? And Allah will say: My Servant, so and so, asked you for a drink, but you did not give him one. Do you not know that if you had given him a drink, you would have found its reward with Me?"
عن أبي هريرة رضي الله عنه قال: قال رسول الله صلى الله عليه وسلم: (إن الله عز وجل يقول يوم القيامة يا ابن آدم مرضت فلم تعدني، قال يا رب كيف أعودك وأنت رب العالمين، قال أما علمت أن عبدي فلانا مرض فلم تعده، أما علمت أنك لو عدته لوجدتني عنده. يا ابن آدم استطعمتك فلم تطعمني، قال: يا رب وكيف أطعمك وأنت رب العالمين، قال: أما علمت أنه استطعمك عبدي فلان فلم تطعمه، أما علمت أنك لو أطعمته لوجدت ذلك عندي. يا ابن آدم استسقيتك فلم تسقني، قال: يا رب كيف أسقيك وأنت رب العالمين، قال: استسقاك عبدي فلان فلم تسقه، أما إنك لو سقيته وجدت ذلك عندي) رواه مسلم.

5. Double Rewards That Last
One gets double rewards from Allah. Aishah may Allah be pleased with her reported that they slaughtered a sheep and gave most of it in charity, so the Prophet pbuh asked: "What is left of it?" She replied: "Nothing is left except its shoulder." He beautifully corrected her perspective and said: "All of it is left except its shoulder." What is given for Allah is what truly remains.
5. أجر مضاعف باق عند الله
ففي سنن الترمذي عن عائشة رضي الله عنها أنهم ذبحوا شاة وتصدقوا بها فقال النبي صلى الله عليه وسلم: (ما بقي منها؟ قالت: ما بقي منها إلا كتفها، قال: بقي كلها غير كتفها).

6. Receiving Aid from Allah
You get Aid from Allah in times of distress. When the Prophet pbuh was terrified by the Angel Gabriel pbuh in the cave, Khadijah may Allah be pleased with her reassured him: "Do not worry, for by Him who has dominion over Khadijah's soul, I hope that you are the Prophet of this nation. Allah would never humiliate you, for you are good to your relatives, you are true to your word, you help those who are in need, you support the weak, you feed the guest and you answer the call of those who are in distress." Narrated by Al Bukhari and Muslim.
6. نيل معونة الله وحفظه
به تنال معونة الله. عندما فزع نبي الله صلى الله عليه وسلم من جبريل عليه السلام في الغار، قالت له خديجة رضي الله عنها: (كلا أبشر، فوالله لا يخزيك الله أبدا، والله إنك لتصل الرحم، وتصدق الحديث، وتحمل الكل، وتكسب المعدوم، وتقري الضيف، وتعين على نوائب الحق) رواه البخاري ومسلم.

7. Survival from the Calamities of Judgment Day
Those who feed others are promised safety. Allah says: (and give food despite their desire for it to the poor, the orphan, and the captive, saying to themselves, "We feed you only for the sake of Allah, seeking neither reward nor thanks from you. We fear from our Lord a horribly distressful Day." So Allah will deliver them from the horror of that Day, and grant them radiance and joy) Surah Al Insan 76: 8 to 11.
7. النجاة من أهوال يوم القيامة
قال الله تعالى: (وَيُطْعِمُونَ الطَّعَامَ عَلَىٰ حُبِّهِ مِسْكِينًا وَيَتِيمًا وَأَسِيرًا * إِنَّمَا نُطْعِمُكُمْ لِوَجْهِ اللَّهِ لَا نُرِيدُ مِنكُمْ جَزَاءً وَلَا شُكُورًا * إِنَّا نَخَافُ مِن رَّبِّنَا يَوْمًا عَبُوسًا قَمْطَرِيرًا * فَوَقَاهُمُ اللَّهُ شَرَّ ذَٰلِكَ الْيَوْمِ وَلَقَّاهُمْ نَضْرَةً وَسُرُورًا) الإنسان 76: 8 إلى 11.