Discretionary punishment (ta'zir): how much is it, and how far may it go?

Yahya bin Abdullah bin Sayfi said that Sayyiduna Umar (may Allah be pleased with him) wrote to Sayyiduna Abu Musa (may Allah be pleased with him): In ta'zir (discretionary punishment), there must not be more than thirty lashes.

Abu Wa'il said that a man wrote to Sayyidah Umm Salamah (may Allah be pleased with her) about a debt of his that she owed, and in that letter he distressed her. So Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) ordered that this man be given thirty lashes. Some of our companions said: All of them cut the skin and raised swelling.

Ash'ath said that al-Sha'bi said: The amount of ta'zir (discretionary punishment) is between one lash and forty lashes.

Al-Harith bin Utbah said that a man who used to revile Sayyiduna Uthman (may Allah be pleased with him) was brought to Umar bin Abd al-Aziz. He asked: "What drove you to revile him?" The man said: "I hate him." They said: "If you hate a man, does that mean you revile him?" So, on his order, he was given thirty lashes.

Talhah bin Yahya said: I was sitting with Umar bin Abd al-Aziz when a man came to him and asked him to fix a stipend for him. He did not allot him a share, so the man said: "He is a disbeliever in Allah if he does not allot him a share!" The narrator said: So he gave him between ten and fifteen lashes.

Sayyiduna Abu Burdah bin Niyar (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "No one shall be given more than ten lashes except in a hadd (prescribed punishment)."

Imran said that al-Sha'bi was asked about four men who testified against a man that he was not the son of so-and-so, while four other men testified that he was indeed the son of so-and-so: what is the ruling on them? He said: "I would remove the punishment from them, because they are four, and I would believe the others."