great, &c. = the great, &c. Compare Mat_24:21. See Jer_30:5-7. Dan_12:1. Nothing to do with Christ's sufferings and death on the cross.
have. Omit.
washed. Greek. pluno. Only here. App-136. Septuagint uses in Psa_51:2, Psa_51:7 for Hebrew. kabas. These wash "their own robes" the standing of works, not of grace. For latter see 1Co_6:11.
in = by. i.e. by virtue of, the en being here the efficient cause. App-104. See Rev_1:5; Rev_5:9, and App-95, note 2, "washing in blood".