A person who rebels against the daylight seeks the cover of darkness to hide his actions, driven by a fear of human judgment while entirely ignoring God. Someone looking to commit adultery with his neighbor's wife [רמב״ן, ביאור שטיינזלץ] waits eagerly for the evening and the dark of night [רלב״ג, מצודת ציון, ביאור שטיינזלץ]. Hating and fearing the light, he relies on the darkness, convinced that no one will be able to see or identify him [מלבי״ם, מצודת דוד, מצודת ציון].
The primary approach among commentators is to view this behavior in physical terms. The dark night serves as a mask, allowing the person to slip away to a hidden location where he can act unseen. This pattern of committing secret offenses, particularly immoral acts and theft, echoes the corrupt behavior that characterized the generation of the Flood [רש״י].
However, there is a deeper psychological and theological layer to this need for concealment [אלשיך]. The sinner suffers from a distorted perception of reality, fearing the eyes of human beings far more than the eyes of God. By attempting to mask his face, he is actually pushing the presence of God out of his own mind. Because the act is naturally shameful and kept secret, his entire focus narrows to avoiding human detection, leading him to completely deny God's active presence in the world.
A distinct perspective highlights a profound irony regarding the outcome of such an act. God is the one who ultimately shapes the face of any child born from this union. If the person truly considered that God is actively involved in creating the new life that might result, he would never fool himself into thinking the act could be kept hidden from Him.