Revelation 9:4

They should not hurt. Locusts destroy vegetation, not men. But these locusts are commanded not to harm any growing plant. Their attacks are to be directed only against unrighteous men.

Those who identify the locust symbol with the Saracens have suggested that this prohibition reflects the policy of the Arab conquerors not to destroy property wantonly or to kill Christians and Jews so long as they submitted to the payment of tribute. Concerning a certain class, Abu-bakr, Mohammed’s successor, is recorded to have said to his soldiers: “‘You will find another sort of people that belong to the synagogue of Satan, who have shaven crowns; be sure you cleave their skulls, and give them no quarter, till they either turn Mahometans or pay tribute’” (quoted in Edward Gibbon, The Decline and Fall of the Roman Empire, J. B. Bury, ed., vol. 5, p. 416). This class has not been definitely identified.

When applied to the Moslem Arabs this restriction may be thought of as representing their policy of permitting the conquered to live. This course was adopted so that the conquered might support the warriors out on conquest.

Have not the seal. Some have suggested that inasmuch as the keeping of the Sabbath is ultimately to be the outward sign of the inner work of sealing by the Holy Spirit (see on Eze. 9:4), the ones attacked by the “locusts” here are those who do not observe the true Sabbath.

In their foreheads. See Eze. 9:4; Rev. 7:3.