This root form (lemma) is used in 3 different forms in the NT: σάκκος (NMS), σάκκους (AMP), σάκκῳ (DMS).
It is glossed in 2 different ways: ‘in sackcloth’, ‘sackcloth’.
OET MAT 11:21 Greek word=σάκκῳ (sakkōi) Morphology=DMS English gloss=‘sackcloth’ SR GNT MAT 11:21 word 27
OET LUKE 10:13 Greek word=σάκκῳ (sakkōi) Morphology=DMS English gloss=‘sackcloth’ SR GNT LUKE 10:13 word 28
OET REV 6:12 Greek word=σάκκος (sakkos) Morphology=NMS English gloss=‘sackcloth’ SR GNT REV 6:12 word 23
OET REV 11:3 Greek word=σάκκους (sakkous) Morphology=AMP English gloss=‘in sackcloth’ SR GNT REV 11:3 word 15