Sirach 23:19
Ben Sira, Ecclesiasticus17 To a fornicator all bread is sweet; he will never weary until he dies. 18 The one who sins against his marriage bed says to himself, "Who can see me? Darkness surrounds me, the walls hide me, and no one sees me. Why should I worry? The Most High will not remember sins." 19 His fear is confined to human eyes and he does not realize that the eyes of the Lord are ten thousand times brighter than the sun; they look upon every aspect of human behavior and see into hidden corners 20 Before the universe was created, it was known to him, and so it is since its completion.
Matthew 6:22
20 But accumulate for yourselves treasures in heaven, where moth and devouring insect do not destroy, and thieves do not break in and steal. 21 For where your treasure is, there your heart will be also. 22 “The eye is the lamp of the body. If then your eye is healthy, your whole body will be full of light. 23 But if your eye is diseased, your whole body will be full of darkness. If then the light in you is darkness, how great is the darkness!
Notes and References
"... Expressions in the Old Testament imply that the Jews thought of the eye as having its own light. 'The light of my eyes – it also has gone from me' (Ps 38[27]:10), 'The light of the eyes rejoices the heart' (Pr 15:30), 'The Lord gives light to the eyes' (Pr 29:13). In Tobit 10:5 we read: 'my child, that I let you go, you who are the light of my eyes'. Though these expressions could be interpreted metaphorically, the point of reference relies on common knowledge of the functioning of the eye. In eight places we read that eyes became darkened (Gn 27:1; 48:10; Dt 34:7; 1 Sm. 3:2; Job 17:7; Ps. 69:23; Lm 5:17; Zch 11:17). The most natural explanation for this metaphor is to recognise the correlation between the eye and the sun. As the heavenly source of light darkens, so too can the bodily source of light dim. In Daniel 10:2–9, Daniel has a vision of a glorious man. He describes him: 'His body was like beryl, his face like the appearance of lightning, his eyes like flaming torches...' (Dn 10:6). Zechariah tells of a vision in which he saw a lamp stand and seven lamps on it (Zch 4:1–14). The record of this vision is followed by a conversation with an angelic interpreter who concludes: 'These seven are the eyes of the Lord, which range through the whole earth' (Zch 4:10) ..."
Viljoen, Francois P. A Contextualized Reading of Matthew 6:22-23: Your Eye is the Lamp of Your Body (pp. 1-9) HTS Theological Studies, Vol. 61, No. 1, 2009