Tafsir of Al-An'am 6:54

{ فقل سلام عليكم } It is either a command to convey God’s peace to them, or a command to initiate the greeting of peace to them, as an act of honor and to soothe their hearts.

{ كتب ربكم على نفسه الرحمة } This is part of what he is to say to them, to gladden them and give them the good news of the vastness of God’s mercy and His acceptance of their repentance.

{ أنه من عمل منكم }

• It is read as innahu (with a kasra on the alif) as an isti'naf (a new sentence), as if the nature of the mercy were questioned, so it was said: "Indeed, whoever among you does..."
• It is read as annahu (with a fatha on the alif) as a substitution for "the mercy."

{ بجهالة } This is in the position of a hal (state), meaning: he did it while he was ignorant. It carries two meanings:

1. He is acting like the ignorant, for whoever does that which leads to harm in the end—while knowing or suspecting it—is among the people of folly and ignorance, not the people of wisdom and prudence. As the poet says: “She said, on the evening I visited her: You acted in ignorance, intentionally, though you were not ignorant.”
2. He is ignorant of the harm and adversity associated with his action. It is the duty of the wise person not to proceed with anything until he knows its nature and condition.

It is said that this was revealed regarding Umar (may God be pleased with him) when he suggested responding to the disbelievers regarding what they asked, not knowing that it was a source of corruption.

{ وكذلك نفصل الآيات ولتستبين سبيل المجرمين }