1. The Obligation Towards Dependents
The first condition: if he has dependents whom he is obliged to support such as children, a wife, and parents, and he does not have a job where he can earn his money to spend on them, then he is not allowed to give away all his money in charity. He is not even allowed to give away money in charity in a way that causes harm to his dependents. Because spending on your children is an obligation, whereas charity is a desirable act. The Messenger of Allah pbuh said: "It is enough for a person to be considered sinful, that he neglects those whom he is responsible to sustain." [Reported by Abu Dawoud]. And he pbuh said: "If you leave your heirs independent of means that is better than if you leave them poor, holding out their hands." [Narrated by Bukhari].
1. وجوب النفقة على المعالين
الحالة الأولى: أن يكون هناك من يلزم المنفق الإنفاق عليهم، كالأولاد والزوجة والوالدين، وليس للإنسان عمل يكسب منه ما يكفي لنفقتهم، فلا يجوز له التصدق بكل ماله، بل لا يجوز له التصدق على وجه يضر بمن تجب عليه نفقتهم؛ لأن النفقة على الأولاد واجبة، والصدقة مستحبة قال رسول الله ﷺ: "كَفَى بِالْمَرْءِ أَنْ يُضَيِّعَ مَنْ يَقُوتُ" رواه أبو داود. وقال ﷺ: "إِنَّكَ أَنْ تَدَعَ وَرَثَتَكَ أَغْنِيَاءَ خَيْرٌ مِنْ أَنْ تَدَعَهُمْ عَالَةً يَتَكَفَّفُونَ النَّاسَ" رواه البخاري.

2. The Consent and Altruism of Dependents
The second case: The ones whom he is supporting give their permission to the provider to give all his money away to charity. So they give preference to the poor over themselves, and in that case, it is permissible that one gives away all his wealth to charity. Allah Almighty says: (They give preference over themselves even though they may be in need).
2. إذن المعالين وإيثارهم
الحالة الثانية: أن يأذن من تلزمه نفقتهم للمتصدق بالصدقة بكل ماله، ويؤثر أهل المتصدق الفقراءَ على أنفسِهِم، فحين ذلك يجوز له أن يتصدق بماله كله، لقوله تعالى: "وَيُؤْثِرُونَ عَلَى أَنْفُسِهِمْ وَلَوْ كَانَ بِهِمْ خَصَاصَةٌ".

3. Possessing a Steady Income
Third case: if someone has an income such as an employee who gets a monthly salary, or a craftsman who sells what he makes, he is allowed to give all his current money to charity because he will earn more to support his children.
3. وجود دخل ثابت
الحالة الثالثة: أن يكون له كسب، كأن يكون موظفًا يكسب راتبًا شهريًّا، أو يكون صانعًا يبيع ما يصنع فإن هذا يجوز له أن يتصدق بكل ماله، لأنه سيكسب ما ينفق به على عياله.

4. The Inner State of the Donor
And although it is permissible for someone to give all his money to charity, there are conditions to do so. Those include that the donor believes in depending on Allah, he is able to be patient towards poverty, and he does not ask people to support him. If those are not possible to achieve then it is not permissible to give all the money.
4. الحالة الباطنة للمتصدق
وحين يقال إن التصدق بكل المال جائز فإن ذلك مشروط بأن يكون المتصدق ممن يحسن التوكل على الله، والصبر على الفقر والتعفف عن المسألة، فإن كان ذلك غير ممكن بالنسبة لذلك المتصدق فليس له أن يتصدق بكل ماله.