Hadith.3305 - And it was narrated by Misma' Kardin from Abu Abdullah (as), regarding four witnesses who testified against a man for adultery, and he was stoned. Then one of them retracted and said
"I doubted my testimony."
Imam (as) said: "He must pay the blood money."
I said: What if he said: "I testified against him intentionally"?
Imam (as) said: "He is to be executed."