Related על ברכות 7:3

These are the Berachot (blessings) which do not seal off with [the phrase] Baruch [Ata Hashem] (Blessed are You Hashem): One that blesses on the fruit, and on the mitzvot, Birkat Hazimun, and the last Beracha in Birkat Hamazon. Rebbi Yossi Hagelili used to seal off the last Beracha in Birkat Hamazon and [therefore] make it long.