Albert Barnes Commentary 2 Kings 4:39

"And one went out into the field to gather herbs, and found a wild vine, and gathered thereof wild gourds his lap full, and came and shred them into the pot of pottage; for they knew them not." — 2 Kings 4:39 (ASV)

A wild vine - This was not a true wild vine, whose fruit is harmless even if not very palatable, but rather some other climbing plant with tendrils. The plant was probably either the Ecbalium elaterium, or “squirting cucumber,” whose egg-shaped, very bitter fruit bursts at the slightest touch when ripe, squirting out sap and seeds. Alternatively, it could have been the Colocynthis, which belongs to the cucumber family, has a vine-shaped leaf, and bears a fruit as large as an orange that is extremely bitter. The drug sold as colocynth is prepared from this fruit, which grows abundantly in Palestine.

His lap full - This literally means “his shawl full.” The prophet brought the fruit home in his “shawl” or “outer garment.”