Abu Musa Al-Ash'ari (May Allah be pleased with him) reported:
The Prophet ﷺ said, "Giving in charity is an obligation upon every Muslim". It was said (to him): "What about one who does not find (the means) to do so?" He ﷺ said, "Let him work with his hands, thus doing benefit to himself and give in charity." It was said to him: "What if he does not have (the means) to do so?" He ﷺ said, "Then let him assist the needy, the aggrieved." It was said: "What about if he cannot even do this?" He ﷺ said, "Then he should enjoin good." He was asked: "What if he cannot do that?" He (the Prophet ﷺ) said, "He should then abstain from evil, for verily, that is a charity from him".

[Al-Bukhari and Muslim].

الخامس والعشرون: عن أبي موس رضي الله عنه ، عن النبي ﷺ قال: "على كل مسلم صدقة" قال : أرأيت إن لم يجد؟ قال: أرأيت إن لم يستطع؟ قال: "يعين ذا الحاجة الملهوف" قال: أرأيت إن لم يستطع؟ قال: "يأمر بالمعروف أو الخير" قال : أرأيت إن لم يفعل؟ قال: يمسك عن الشر فإنها صدقة" ((متفق عليه)) .