Silsilat al-Ahadith al-Sahihah

The Messenger of Allah (peace and blessings be upon him) said: "When any one of you relieves himself, he should perform istinja with three times (and according to one narration) with three stones." This hadith is narrated from Sayyiduna Jabir, Sayyiduna Sa'ib bin Khallad, and Sayyiduna Abu Ayyub Ansari (may Allah be pleased with them).

It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that the Noble Prophet (peace and blessings be upon him) said: "Whoever performs istinja with stones, let him use stones three times."

Sayyiduna Salamah bin Qais Ashja’i (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: “When you perform ablution, clean your nose, and when you use stones for istinja (purification), use an odd number (of stones).”

Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates that the Noble Prophet (peace and blessings of Allah be upon him) said: "When any person performs istinja (cleansing) with stones, he should use an odd number of stones, and when he blows his nose, he should also do so an odd number of times."