Is it true that Bilal, may God be pleased with him, used to pray two rak'ahs after ablution, in praise of God?

What is established from Bilal is that he used to pray two rak'ahs after every ablution and two rak'ahs after the adhan. Bilal said: "O Messenger of Allah, I never called the adhan except that I prayed two rak'ahs, and I never suffered a minor ritual impurity except that I performed ablution immediately." As for anything other than this, it was not mentioned.