A.T. Robertson Commentary Matthew 26:38

"Then saith he unto them, My soul is exceeding sorrowful, even unto death: abide ye here, and watch with me." — Matthew 26:38 (ASV)

Watch with me (γρηγορειτε μετ' εμου). This late present from the perfect εγρηγορα means to keep awake and not go to sleep. The hour was late and the strain had been severe, but Jesus pleaded for a bit of human sympathy as he wrestled with his Father. It did not seem too much to ask. He had put his sorrow in strong language, "even unto death" (εως θανατου) that ought to have alarmed them.