בָּר֥וּךְ אַתָּ֖ה בְּבֹאֶ֑ךָ וּבָר֥וּךְ אַתָּ֖ה בְּצֵאתֶֽךָ׃
Béni seras-tu à ton arrivée, et béni encore à ton départ!
Rashi
ברוך אתה בבאך וברוך אתה בצאתך BLESSED SHALT THOU BE WHEN THOU COMEST IN, AND BLESSED SHALT THOU BE WHEN THOU GOEST OUT — This means: may thy departure from this world be as sinless as was thy coming into the world (Bava Metzia 107a).
Chizkuni
ברוך אתה בבואך...ובצאתך, ”you will be blessed when you are coming in ...and when you are going out.” This refers to coming home from war and going out to do battle. The expressions בא and צאת, are used in this sense in Numbers 27,17: אשר יצא לפניהם ואשר יבא לפניהם , “who will go out in front of you when going to war and before you when returning from battle.”
Ibn Ezra
your going Either to celebrate the festivals, or to conduct commerce, or to bring in the spoils of battle; or all everyday comings and goings (meaning, you will succeed in everything you do — cf. the subsequent passage [: 20], where the reverse of this blessing is stated explicitly).