﴿ سَلَٰمٌۭ قَوْلًۭا مِّن رَّبٍّۢ رَّحِيمٍۢ ﴾

“peace and fulfillment through the word of a Sustainer who dispenses all grace.”

“Peace!” salāmun is a subject — the word qawlan is its predicate that is peace by way of a word from a Lord Who is Merciful to them in other words He says to them ‘Peace be on you!’