In Greek this sentence begins with the particle oun, which New English Bible and New American Bible translate “at this.” (See under 2.18.) Good News Translation introduces a new paragraph.

The people is literally “the Jews.” See Appendix I.

Started grumbling (New English Bible “began to murmur”; New American Bible “started to murmur”) renders the force of the Greek imperfect. Revised Standard Version and Moffatt translate “murmured” and Jerusalem Bible “were complaining.” The verb grumbling is the simple form of the verb used in the Septuagint account of the grumbling of the Israelites during the Exodus (see Exo 16.2,7,8). The verb denotes more of complaint than of open hostility. Elsewhere in John it is used in 6.43,61; 7.32; and in the remainder of the New Testament only in Matthew 20.11; Luke 5.30; and 1 Corinthians 10.10 (twice). The noun form of the same stem occurs in 7.12. An equivalent of started grumbling may be “started speaking against” or “started complaining to one another about him.”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on the Gospel of John. (UBS Handbook Series). New York: UBS, 1980. For this and other handbooks for translators see here .