Who begins the stoning?

Abd al-Rahman bin Abi Layla said: When witnesses testified to zina (unlawful sexual intercourse) before Sayyiduna Ali (may Allah be pleased with him), he would order the witnesses to throw stones, then he would throw stones, then the people would throw stones. And when there was a confession, he himself would begin and throw stones at the person, then the people would throw stones at the person.

Abd al-Rahman bin Abdullah bin Mas'ud said: Sayyiduna Ali (may Allah be pleased with him) said: O people! Zina (unlawful sexual intercourse) is of two kinds: secret zina and open zina. Secret zina is when witnesses testify to the zina, so the witnesses will be the first to throw stones, then the ruler, then the people. Open zina is when pregnancy becomes apparent or there is a confession, so the Imam will be the first to throw stones. The narrator said: He had three stones in his hand, and he threw one stone at the woman, and it struck the opening of her ear, and she began to spin around, and the people threw stones.

The aforementioned statement of Sayyiduna Ali (may Allah be pleased with him) is also reported in the same words from Abd al-Rahman through this chain.

Amr bin Nafi' said: Sayyiduna Ali (may Allah be pleased with him) said: Stoning is of two kinds: one stoning in which the ruler throws stones, then the people; and one stoning in which the witnesses throw stones, then the ruler, then the people.

The narrator said: I asked al-Hakam: What is the stoning of the Imam? He said: When the woman gives birth or she confesses. And the stoning of the witnesses is when they have testified.

Shu'bah said: I asked al-Hakam: What is the ruler's stoning? He said: When the woman gives birth or confesses. And when witnesses testify, the witnesses themselves will begin.