Where does “beannaigh” come from?

beannaigh (Irish) comes from Middle Irish bennaigid, from Old Irish bennachaid, from Old Irish bendachaid, from Latin benedīcō, from Latin dīcō, from Latin -tiō, from Latin dissertātiō, from Latin dissertus — small stone, pebble; gravel, rubble.

beannaigh (Irish): bless, hallow; greet; inflection of beannach: ##...

Definitions

bless, hallow; greet; inflection of beannach: ##...

Ancestry of “beannaigh”, step by step

Step	Language	Word	Meaning
1	Middle Irish	bennaigid	—
2	Old Irish	bennachaid	to bless
3	Old Irish	bendachaid	—
4	Latin	benedīcō	to speak well of someone, commend
5	Latin	dīcō	to say, talk, speak, utter, mention
6	Latin	-tiō	tion, -ation, -ing
7	Latin	dissertātiō	(spoken) dissertation, discourse, disquisition
8	Latin	dissertus	arranged, disposed; explained
9	Latin	disserere	second-person singular future passive indicative...
10	Latin	dis-	asunder, apart, in two; reversal, removal;...
11	Latin	calceus	shoe
12	Latin	calx	limestone; chalk; the finish line
13	Ancient Greek	χάλιξ	small stone, pebble; gravel, rubble

Every word from Ancient Greek χάλιξ →Every word from Latin -tiō →Every word from Latin dis- →