Dukkha: Suffering
A siege shuts every door at once: no bread inside the wall, an army outside it, and death in the dust where four men with leprosy are sitting. They have run out of comfortable options, which is the honest shape of things all the time, usually hidden by a full pantry. Hunger only strips off the padding and lets them see the walls.
Maraṇasati: Mindfulness of death
Counting death three times over, in the city, on this spot, in the enemy camp, is exactly this practice. Most people keep death at arm's length, like a bill that comes due many years from now; these men hold it up close, and it steadies them rather than freezing them. Once you have said aloud that you die on every road, the roads stop looking so different, and you can choose one.
Yoniso manasikāra: Wise attention
Laying the three possibilities side by side and following each to where it ends is attention doing its proper work. There is no panicking at the gate, no arguing about whose fault the siege is, just one option taken up at a time and asked where it lands. Anyone can do this with a hard decision, the way you price out three routes before a long drive, and the fog usually lifts.
Saṃvega: Urgency
"Now therefore come" is the sound of it, the jolt that turns a grim reckoning into standing up. Sitting at that gate could have gone on all evening, each man waiting for someone else to speak first, until their own arithmetic put them on their feet. The same jolt is what gets a person to begin practicing today instead of next year.
Appamāda: Heedfulness
Sitting still kills them as surely as the famine does, and that is the heart of it: heedlessness is a slow death, diligence is moving while there is still light. Walking toward the Syrian camp risks nothing they had not already lost. Every hour spent at the gate had been costing them the same thing, only quietly.