John Milton's sonnet on his blindness includes an interesting reference to the parable of the talents. In this parable Jesus told his disciples of a rich man who gave three servants money to invest. A "talent" was a vast sum of money. One servant was given 10 talents; another 3 talents; a third servant only 1 talent. The rich man said he would be gone for some time, and that he expected to see a return on his investment when he returned. The first two servants did rather well, but the third servant buried his talent and said he was afraid to invest it because he thought he might lose it and knowing what a severe man the rich man was he didn't want to disappoint him. The rich man was extremely angry with his servant and ordered him killed immediately. .
This is what Milton was referring to when he wrote about "that one talent which is death to hide / lodg'd with me useless though my soul more bent / to serve therewith my maker and present / my true account lest he returning chide" The biblical allusion is clearly related to this parable of the talents; and Milton was aware that now that he was blind he would be less able to give a true account of his abilities. .
Another Biblical passage alluded to is the one that says, "They that wait upon the Lord shall renew their strength; they shall mount up with wings as eagles; they shall run and not be weary; they shall walk and not faint." Milton ends his poem by saying "They also serve who only stand and wait." He was clearly thinking of the scripture from Isaiah mentioned above when he wrote this concluding line.
All in all, Milton's biblical allusions lend a powerfully poignant sense of pathos and urgency to his very real physical dilemma. How could he adequately serve God now that he was blind? He didn't know and he was close to despair. But he also knew that "Patience" that gift of the Holy Spirit according to the new testament would "prevent" his "murmur" and help him to endure the despair that threatened to engulf him.