The antecedent of the suffix has been understood in different ways. It could refer to God’s faithfulness, but in this case one would expect a first person suffix (the original form of the LXX has “my faithfulness” here). Others understand the “vision” to be the antecedent. In this case the reliability of the prophecy is in view. For a statement of this view, see J. J. M. Roberts, Nahum, Habakkuk, and Zephaniah (OTL), 111–12.