Qoheleth here focuses on the creature as a worshiper and addresses himself to conduct that is appropriate in the presence of God. The language is more restrained than that of the prophet since the observed worshiper is well-meaning but forgetful rather than hypocritical (Kidner, 52). There are three separate sayings in this passage.
First, Qoheleth urges caution relative to the frequency and quality of approach to God (v. 1). While not rejecting sacrifice (his objection to the fool's sacrifice is probably due to misuse), Qoheleth stresses the importance of listening, i.e., of understanding and obeying.
Second, he warns against impetuosity and multiplication of words during prayer (vv. 2-3). Words should be carefully weighed before they are uttered. In prayer an adequate distance of awe and respect must be maintained.
Third, he speaks against hastily made vows (vv. 4-7). Better not to make a vow than to make one and not fulfill it. Evasion of a vow by alleging that it was a mistake does not exonerate the worshiper. Throughout this section Qoheleth calls for few and careful words when in God's presence.