Luke 23:48

23:48 And all the crowds that had assembled for this spectacle, when they saw what had taken place, returned home beating their breasts. ¹ 

Luke 18:13

18:13 The tax collector, however, stood ²  far off and would not even look up ³  to heaven, but beat his breast and said, ‘God, be merciful ⁴  to me, sinner that I am!’ ⁵ 

[23:48]  ¹ sn Some apparently regretted what had taken place. Beating their breasts was a sign of lamentation.

[18:13]  ² tn Grk “standing”; the Greek participle has been translated as a finite verb.

[18:13]  ³ tn Grk “even lift up his eyes” (an idiom).

[18:13]  ⁴ tn The prayer is a humble call for forgiveness. The term for mercy (ἱλάσκομαι, Jilaskomai) is associated with the concept of a request for atonement (BDAG 473-74 s.v. 1; Ps 51:1, 3; 25:11; 34:6, 18).

[18:13]  ⁵ tn Grk “the sinner.” The tax collector views himself not just as any sinner but as the worst of all sinners. See ExSyn 222-23.