וַיֵּ֧רֶד שִׁמְשׁ֛וֹן וְאָבִ֥יו וְאִמּ֖וֹ תִּמְנָ֑תָה וַיָּבֹ֙אוּ֙ עַד־כַּרְמֵ֣י תִמְנָ֔תָה וְהִנֵּה֙ כְּפִ֣יר אֲרָי֔וֹת שֹׁאֵ֖ג לִקְרָאתֽוֹ׃
삼손이 그 부모와 함께 딤나에 내려가서 딤나의 포도원에 이른즉 어린 사자가 그를 맞아 소리 지르는지라
Rashbam
גור אריה יהודה, an expression similar to כפיר אריות, (Judges 14,5) the young, not fully grown lion is called גור, whereas the fully mature lion is known as כפיר as we know from Ezekiel 19,2 בתוך כפירים רבתה גוריה, “a young lioness crouched among the fully grown lions.” The young lion enjoys the advantage of speed and self-confidence, hence more aggressiveness, over an aging lion. It is not surprising therefore that when complimenting Yehudah, Yaakov compares him to a young lion rather than to a fully mature one who is already on the way to decline.
Radak
ויעל, here the trip to Timnatah is described as an ascent, whereas in Judges 14,5 Shimshon is described as descending to that town. It all depends on the location from which one sets out.