Valmiki Ramayana Kishkindha Kanda Sarga 42 Shloka 53

मासात् more than a month, ऊर्द्वम् beyond that, न वस्तव्यम् you should not stay, वसन् while staying, मम to me, वध्यः to be killed, भवेत् you may be, युष्माभिः by you सहैव along with you, मे my, शूरः brave, श्वशुरः fatherinlaw, गमिष्यति will go

'If you tarry beyond a month, you will be slain. My fatherin law, the brave hero will go with your group.