Sforno on Genesis 48:11/ספורנו על בראשית מ״ח:י״א

1גם את זרעך, the ones to whom the description קהל עמים applied. (verse 4) Yaakov continued (perhaps not audibly); this is when He said to me that He blessed me, i.e. Yaakov had repeated this blessing by G’d in his conversation to Joseph without being that specific. [I had to paraphrase this to make the author intelligible. Ed.] As a result of that blessing which I received, my blessing to you now will be effective, so that by blessing his sons he also blessed Joseph at the same time.