On the authority of Abu Harayrah (may Allah be pleased with him) from the Prophet ﷺ, who said: Allah (mighty and sublime be He) said:
Spend (on charity), O son of Adam, and I shall spend on you.

It was related by al-Bukhari (also by Muslim).

عَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ، أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ:
" قَالَ اللَّهُ: أَنْفِقْ يَا ابْنَ آدَمَ، أُنْفِقْ عَلَيْكَ ".