Arabic text
عن خَوْلَةَ بِنْتَ حَكِيمٍ السُّلَمِيَّةَ قَالتْ: سَمِعْتُ رَسُولَ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ يَقُولُ: «مَنْ نَزَلَ مَنْزِلًا ثُمَّ قَالَ: أَعُوذُ بِكَلِمَاتِ اللهِ التَّامَّاتِ مِنْ شَرِّ مَا خَلَقَ، لَمْ يَضُرَّهُ شَيْءٌ حَتَّى يَرْتَحِلَ مِنْ مَنْزِلِهِ ذَلِكَ».
Translation
Khawlah bint Hakīm (may Allah be pleased with her) reported: I heard the Messenger of Allah (may Allah's peace and blessings be upon him) say: "Whoever alights somewhere and then says: '‘A‘ūdhu bi kalimātillāh at-tāmmāti min sharri ma khalaq (I seek refuge in the perfect words of Allah from the evil of what He has created)', nothing will harm him until he leaves that place."
Explanation
The Prophet (may Allah's peace and blessings be upon him) teaches his Ummah how to seek refuge with Allah Almighty in an effective way that wards off anything fearful when a person stops anywhere during a journey, a picnic, or otherwise. In such a situation, one should seek refuge in the words of Allah - which contain perfect excellence, blessing, and benefit and are free from any defect or deficiency - from the evil of any created being. Thus, he will be safe from anything harmful for as long as he stays in that place.
Source: HadeethEnc.com