سنن النسائي

It was narrated that Sa'sa'ah bin Mu'awiyah said: "I met Abu Dharr and said: 'Tell me a Hadith.' He said. Yes, the Messenger of Allah (ﷺ) said: There is no Muslim worshiper who spends from each type of his wealth on a pair (of things) in the cause of Allah, but the keepers of Paradise will welcome him, all of them calling him to what they have (of reward).' I said: "How is that?" He said: "If it is camels, he gives two, and if it is cows, he gives two.'"