Tafsiran Pengkhotbah 5:1: Rashi & Ibn Ezra

To utter a word before God. To speak critically toward [God] above.¹Alternatively, “do not let your heart be hasty” to voice complaints before God, “for He is in heaven and you are on earth,” i.e., He alone knows what is good for you and whatever he does is for the best. See Maseches Berachos 61a and Maharsha there.

Do not be rash — Do not let words come out of your mouth before Him in His house rashly. And let your heart not be quick — unless you understand them, for the heart is as if it were lost and straying after worldly engagements. Thus the anointed of the LORD said: Your servant has found it in his heart (II Samuel 7:27). And know that God stands over you and sees you and years your words, for He is in heaven in the highest of the high heights, and you are on earth, and nothing is lower than you. Thus let your words be little so as not to endanger yourself, like the high priest on the Day of Atonement who would pray a short prayer (M. Yoma 5:1) and leave.

For God is in heaven and you are on earth. And even if the weak one is above, and the strong one below, the fear of the weak one is upon the strong one, how much more so when it is the strong one [=God] Who is above and the weak one who is below.