Albert Barnes on 1 Corinthians 7:9

But if they cannot contain. If they have not the gift of continence; if they cannot be secure against temptation; if they have not strength of virtue enough to preserve them from the danger of sin, and of bringing reproach and scandal on the church.

It is better. It is to be preferred.

Than to burn. The passion here referred to is often compared to a fire. See Virg. AEn. iv. 68. It is better to marry, even with all the inconveniences attending the marriage life in a time of distress and persecution in the church, 1Cor 7:26, than to be the prey of raging, consuming, and exciting passions.

(+) "contain" "have not continence" (b) "let them marry" 1Timm 5:14