הַשְׁלֵ֤ךְ עַל־יְהוָ֨ה ׀ יְהָבְךָ֮ וְה֪וּא יְכַ֫לְכְּלֶ֥ךָ לֹא־יִתֵּ֖ן לְעוֹלָ֥ם מ֗וֹט לַצַּדִּֽיק׃
네 짐을 여호와께 맡겨 버리라 너를 붙드시고 의인의 요동함을 영영히 허락지 아니하시리로다
Tov haLevanon
we pray to Him on our needs and troubles, even though nothing is hidden from His eyes, and He knows our needs better than we do, and He provides sustenance to all living things according to its deeds and according to what His wisdom decreed, nevertheless, we pour our prayers to Him in order to feel our great need for Him and placing our trust in Him, as the author writes later in number 18.
Tosafot Yom Tov
ANYONE WHO FORGETS. “Anyone” means to include even one who forgets out of laziness, as I will explain below. Midrash Shmuel writes that even one who forgets because he is busy providing for his family is as if he has forfeited his life, for the verse clearly says, “cast your burden upon G-d” (Psalms 55:23), and only he who forgets due to the difficulty of the material is exempt.
Rashi
One should cast his trust upon the Lord Heb. גֹּל like לגל, lit. to roll. A person should roll his burden and his load upon His Creator so that He rescue him.