The Prophet (ﷺ) said, "When a Muslim spends something on his family intending to receive Allah's reward it is regarded as Sadaqa for him."
Sahih al-Bukhari Book 69, Hadith 1
← Previous Hadith The Prophet (ﷺ) said to those who were involved in a case of Lian, "Your accounts are with Allah. One of you two is a liar. You (husband) have right on her (wife)." The husband said, "My money, O Allah's Apostle!" The Prophet (ﷺ) said, "You are not entitled to take back any money. If you have told the truth, the Mahr that you paid, was for having sexual relations with her lawfully; and if you are a liar, then you are less entitled to get it back."

Sahih al-Bukhari Book 68, Hadith 95 Next Hadith → Allah's Messenger (ﷺ) said, "Allah said, 'O son of Adam! Spend, and I shall spend on you."

Sahih al-Bukhari Book 69, Hadith 2