Sirach 41:20

20 And of silence before them that salute thee; and to look upon an harlot;

Sirach 41:20 In-Context

18 Of an offence before a judge and ruler; of iniquity before a congregation and people; of unjust dealing before thy partner and friend;
19 And of theft in regard of the place where thou sojournest, and in regard of the truth of God and his covenant; and to lean with thine elbow upon the meat; and of scorning to give and take;
20 And of silence before them that salute thee; and to look upon an harlot;
21 And to turn away thy face from thy kinsman; or to take away a portion or a gift; or to gaze upon another man's wife.
22 Or to be overbusy with his maid, and come not near her bed; or of upbraiding speeches before friends; and after thou hast given, upbraid not;

The Brenton translation of the Septuagint is in the public domain.