Halakhah su Esodo 18:9

The late Brisker Rav found support for this opinion in the utterance of Jethro, "Blessed be the Lord, who has delivered you out of the hands of the Egyptians and out of the hands of Pharaoh, and has delivered the people from under the hand of the Egyptians" (Exodus 18:10). This declaration, remarked the Brisker Rav was tantamount to the birkat ha-gomel and was pronounced by Jethro upon the deliverance of Israel, a deliverance in which he himself did not personally share. Scripture carefully records, "And Jethro rejoiced for all the goodness which the Lord had done to Israel" (Exodus 18:9), indicating that the blessing can be pronounced by others not personally affected by the event only if the blessing is occasioned by genuine jubilation as demanded by Rema and as explained by Taz, Oraḥ Hayyim 219:3.