The incident occured at 5:12 p.m. on the 1500 block of West Courtland Street.
Police say the victim was loading a food delivery for the Words In Action Ministries when he was approached by an unknown man and woman.
The pair began asking the man questions about the food when the man suddenly pulled out a Bowie style knife and demanded cash.
They got away with $43 before fleeing east on Courtland Street towards Mole Street.
There were no injuries reported.
The first suspect is described as a black male, around 30 years-old, 5'10"-6'0" tall with a slim build and long goatee. He was wearing white zip up hooded jacket, blue jeans, black knit hat and brown boots.
The second suspect is described as a black female, mid to late 20s, and 5'5" tall with a heavy build. She was wearing a blue bubble jacket, red sweatpants and black boots.
Anyone with information is asked to call police at 215.686.TIPS (8477) or text a tip to PPD TIP or 773847.
Tips will remain confidential.