This is to explore the practical meaning of the lamenting prayer by looking into the horizons of the lament in the Psalms. It is also to suggest that the languages and the ways of prayer in the lament of the Psalms are important to be used for prayer languages, as imperfect creatures we have no choice but to plea to God about our internal negative emotions. For this, it first looks into the characteristics of the metaphoric languages in the Psalms. It discloses that the metaphoric language in the Psalms not only speaks to us but also allows freedom for us to speak, and emphasizes that the metaphoric languages help us develop our emotions which brings a dynamic to our experiences. In this context, it suggests that the languages of the lament in the Psalms have the characteristics for us to develop and experience a new personality. Furthermore, it discusses that the lament of the Psalms offers the fundamental aspects which help us pray to God when we feel guilt, pain, sorrow, anger and discomfort. Then, it discloses that the lament of the Psalms guides us to a new place where we can leave everything to God’s sovereignty. Finally, it suggests the practical meaning of the complaining prayers in the lament of the Psalms. That is complaining prayer as a denial of evil, complaining prayer as evidence of being fully alive, complaining prayer as God’s curriculum, God as a recipient of complaining prayer, complaining prayer as the transforming journey of a person are suggested.