Walk through Amos, verse by verse, with the great Bible Commentaries of Matthew Henry (1662 - 1714) & Adam Clarke (1760 - 1832)
{For the Lord God saith these things, The city of which a thousand went out, an hundred shall be left therein; and of which an hundred went out, ten shall be left therein, in the house of Israel.}Wycliffe's Bible
The city that had a militia, 1000 strong, and, in the beginning of the war, had furnished out 1000 effective men, able-bodied and well-armed, when they come to review their troops after the battle, shall find but 100 left; and, in proportion, the city that sent out 100 shall have but ten come back, so great a slaughter shall be made, and so few left to the house of Israel for the public service and safety.’’ Scarcely one in ten shall escape of the hands that should relieve this abject, this dejected, nation.
5:3
For thus saith the Lord GOD; The city that went out by a thousand shall leave an hundred, and that which went forth by an hundred shall leave ten, to the house of Israel.
KJV 
{For the Lord God saith these things, The city of which a thousand went out, an hundred shall be left therein; and of which an hundred went out, ten shall be left therein, in the house of Israel.}Wycliffe's BibleThe city that had a militia, 1000 strong, and, in the beginning of the war, had furnished out 1000 effective men, able-bodied and well-armed, when they come to review their troops after the battle, shall find but 100 left; and, in proportion, the city that sent out 100 shall have but ten come back, so great a slaughter shall be made, and so few left to the house of Israel for the public service and safety.’’ Scarcely one in ten shall escape of the hands that should relieve this abject, this dejected, nation.