Or else - If he is not able. If he is satisfied that he would be defeated.
An ambassage - Persons to treat with an enemy and propose terms of peace. These expressions are not to be improperly pressed in order to obtain from them a spiritual signification. The general scope of the parable is to be learned from the connection, and may be thus expressed:
1. Every man who becomes a follower of Jesus should calmly and deliberately look at all the consequences of such an act and be prepared to meet them.
2. Men in other things act with prudence and forethought. They do not begin to build without a reasonable prospect of being able to finish. They do not go to war when there is every prospect that they will be defeated.
3. Religion is a work of soberness, of thought, of calm and fixed purpose, and no man can properly enter on it who does not resolve by the grace of God to fulfil all its requirements and make it the business of his life.
4. We are to expect difficulties in religion. It will cost us the mortification of our sins, and a life of self-denial, and a conflict with our lusts, and the enmity and ridicule of the world. Perhaps it may cost us our reputation, or possibly our lives and liberties, and all that is dear to us; but we must cheerfully undertake all this, and be prepared for it all.
5. If we do not deliberately resolve to leave all things, to suffer all things that may be laid on us, and to persevere to the end of our days in the service of Christ, we cannot be his disciples. No man can be a Christian who, when he makes a profession, is resolved after a while to turn back to the world; nor can he be a true Christian if he "expects that he will" turn back. If he comes not with a "full" purpose "always" to be a Christian; if he means not to persevere, by the grace of God, through all hazards, and trials, and temptations; if he is not willing to bear his cross, and meet contempt, and poverty, and pain, and death, without turning back, he "cannot" be a disciple of the Lord Jesus.

Or else, while the other is a great way off,.... Upon his march, with resolution to come up and give battle, though as yet at a distance:
he sendeth an ambassage; or men, with an embassy to him:
and desireth conditions of peace; greatly to his disadvantage and reproach: so to give out, and leave off fighting with sin, Satan, and the world, and make peace with them, is shameful and scandalous; but on the other hand, such who have engaged in this war, should pursue it with rigour and courage; considering that God is on their side; that Christ is the captain of their salvation; that the Spirit of God that is in them, is greater than he that is in the world; that angels encamp around them; that it is a good cause they are engaged in; that they have good weapons, the whole armour of God provided for them; are sure of victory, and shall at last enjoy the crown of life, righteousness and glory.