Self-praise is no recommendation

Self-praise is no recommendation.

Prov. If you praise yourself, people will think that you are boastful and will not respect you. After listening to the lawyer brag about his achievements for a solid half hour, I decided I would find someone else to handle my case. Self-praise is no recommendation.
See also: no
References in classic literature ?
Sophronia, darling, Mr and Mrs Boffin will remind you of the old adage, that self-praise is no recommendation.
WITH regards to Operation Furan by South Wales Police (Echo, September 30) it would appear that Chief Superintendent Josh Jones has not heard that self-praise is no recommendation.