Surgery is an ancient medical specialty that uses operative manual & instrumental techniques on a patient to investigate or to treat a pathological condition.
The term “lesion” in a broad meaning word in medical field, here it can be taken as abscess, boils, furunculosis, carbuncles, tumors & etc which get infected with pus collection or putrefaction.
1. Hazrat Abu Hurairah رضي الله عنه says that Nabi ﷺ ordered a doctor to incise an abscess on the abdomen of a man. Nabi ﷺ was asked, "Does medicine help, Oh! Nabi ﷺ, Nabi ﷺ replied: “He (SWT) Who Has Sent down the disease, Has also sent down whatever He Wills of the Cure”.
[Al-Jaamus Sagir: 1688]